Inexpensive LinuxCNC interface for MPCNC

Software / Firmware
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It’s taken a while, but I finally got the Breakout board and LinuxCNC to work. While the mobo did not have a pink parallel port socket, the Bios showed a parallel port and I found it was a series of 26 pins at the bottom of the board.

I needed an adapter and bought this

I also had to buy a parallel port cable and resorted to importing as I could not find anything local.

With all this and using the cnc shield as the driver board got it working. I have not had any success with a TB6560 driver, but I at least know the breakout board works and LinuxCNC may be worth struggling with.

Got to give Mach3 a go too.

I have another PC with a parallel port socket, so will try that. Most cheap modern mobo’s have few expansion ports so I expect LinuxCNC needs to adapt or face a bleak future.

Keep persevering folks.

 

 

 

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The answer to that I think is the pci cards or mesa cards most recently discussed in this thread.

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Hi,

I have now got 2 PC’s with parallel ports functioning with linuxCNC. Also managed to get the TB6560 driver to work as well.

My next task is to try using a RAMPS 1.4 shield to make use of the breakout boards 5 axis outputs. I imagine the total RAMPS 5A fuse on the power supply to the drivers should limit use to Nema 17 size motors.

Now, what can I use it with!

 

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Discourse discourages necro-ing old posts, but I figure that folks who are interested in this are still interested.

For some reason when I first started looking at making/buying a CNC, LinuxCNC just didn’t come up on my radar. I think at the time because it was all parallel port, I just assumed it was a legacy system that hadn’t kept up with the new hardware boards coming out.

I have tons of experience with Linux. In the span of nine years I got a small grade school transitioned from 10 virus laden Windows 95 machines in one computer lab to each class having ten PCs running with Linux Terminal Server on Ubuntu. Chromebooks hadn’t quite made it to prime time so I scoured government surplus and the local banks for used hardware. It was amazing how much computing we were able to build out for next to nothing, just getting the network built up.

I’m poking around with LinuxCNC because there are some things that intrigue me like adding a fourth axis. I’m kind of deep in the weeds though looking at cards and all the connecting bits. Don’t know if I will ever get serious about the hardware, but I know the interface is pretty cool. But having to buy anything extra is where I get stuck. Always liked that my Linux machines never cost me anything.

And I have a tinyG sitting around doing nothing at the moment that I should be getting to run the sand table.

So many dreams, so little time.

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As one who loves Linux and free/open source, like you, I hate spending any more $$$ than absolutely necessary to do stuff I want to do. While far from being a Linux “power user” I generally get by… and don’t do Windows if I can at all avoid it.

Between early retirement from industry (a world-wide corporation and a massive Unix/Linux shop) and full retirement when I turned 65, a span of 8 years, I worked in the technology department of the local, rural, school system. I hated the solidly entrenched Windows environment and sought to use Linux wherever I could… even managed, like you, to set up a “test classroom/lab” using Ubuntu’s LTS and nothing but old, out-dated, PCs, destined for the recycler. Sadly, it was a remote classroom on the edge of the campus, teachers wouldn’t bring their classes over, and it sat – running – for 2-years solid, without rebooting, and virtually no use other than me remoting in and checking on things. We also used thin-clients… again, not popular. Windows netbook 1-to-1 deployment was a nightmare. Thankfully, after I’d been retired a couple of years, a couple of former tech workmates managed to get Chromebooks into the system… the Google ecosystem had already gained acceptance…and the transition since has been nothing short of spectacular. Thrilled, I never believed it could happen so fast…

When I first started this CNC stuff I used EMC2/LinuxCNC… I was an avid Linux advocate (hence my screen-name) and loved live CDs and reusing old, “worn out” PC’s to run it. I did virtually all my early needle-cutter development using it. Finally, Ryan created the MPCNC and I transitioned quite easily to Marlin/Grbl based machines… and have built/rebuilt numerous machines and variants since.

But, I ran into a couple of fellows on RCGroups a year or so ago, both LinuxCNC users, and my interest in LinuxCNC was renewed… and I was ready for something different. Since I’d rather play with my machines than actually use them for anything productive, I set about switching my FoamRipper “guinea-pig” machine over to LInuxCNC… and had a blast doing it. It was a trip down memory lane.

Determined not to spend any $$$ on it, however, I dug around in my pretty well-stocked stash of parts… pulled together an old PC, a LinuxCNC iso, and a couple of common inexpensive CNC interface boards I already had on hand… a parallel-port breakout board and a CNC V3 inteface card (without the Uno). Recognizing the step/direction controls out of the PC/LinuxCNC should be reasonably compatible with the little step-stick drivers we all know and love, I devised the little board set I detail in this thread… and FoamRipper once again came to life. I documented my journey, answered a few questions here and there, and, somewhat understandably, there’s been little interest shown since. It’s a powerful setup (though I really never did more than the “basics” with it) and it is more for tinkerers than the typical mainsteam user. And, it’s a bit bulkier, of course, with the PC… though FoamRipper, itself, is easily broken down to move, as I have since done.

Alas, my curiosity once again satisfied, I’ve since transitioned FoamRipper back to Marlin and added a laser to the tool head. But, over the past several months, I’ve played around with Grbl quite a bit… and grown quite fond of it. So much so, I’m seriously considering converting FoamRipper yet again. Plus I’m pretty involved helping support Edward Chew’s Grbl-based ERC TimSav needle-cutter system , a minimalist KIT machine, that can be built for less than $200 and has a rapidly growing community of RC’ers.

Oh, well… I’m not sure why I wrote all this, other than to compare our journeys, but IMO LinuxCNC is a really fun and powerful system if you are willing to spend the time learning it. I, for one, would love to see what you, with your strong Linux background and the experience you’ve gained with CNC since, could do with it.

– David

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Thanks for the detailed and personal response. Yes. Kindred spirits meet. I started with the Fedora LTSP but then transitioned to Ubuntu once that got built out and integrated. To be able to manage student desktops/accounts was just so easy and free. I know that Windows Server has educational discounts, but even that is just way to much overhead. I got to start early on in 2005 so I just kept learning as releases came out.

One of my favorite projects was converting the school library into an open source library information system. The book data format, MARC, is a fascinating legacy monstrosity. Kind of resembles gcode in that ancient data structure that just kept getting additions to it. There is a pretty cool app that can manage MARC records and do the conversion necessary, but that was when I learned sed, perl, grep and regular expressions to get the 8,000 books in shape for the export/import.

Got into raspberry pis at the end of my run so it was a bit easier to get into microcontrollers.

I’m still wrapping my head around the driver portion of this. What do I want to spend and what minimum hardware versus doing a home brew solution. We’ll see what comes up.

That needle machine is so cool. I hadn’t come across these until I came to this forum. so many cool toys.

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We had windows machines in school. And a lot of macs, because they were so deeply discounted for education. The windows machines were relatively easy to get into, and although they tried to stop us, we installed all kinds of games and played them during classes. Windows has gotten a lot more secure, but if those boxes were Linux, we would have had a tougher time. Although, there is no security without physical security, and I’m sure we would have found a way.

David, have you tried easypcb? I bet you would enjoy making a little break out board for the drvs and parallel port. It doesn’t cost much to get a custom pcb made. They always come in qty:10, so you could sell the rest, or use them as coasters.

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Hey, Jeff! I haven’t given a lot of thought to making a custom board… though I would have practically killed to have the tools and capabilities we have now, earlier in my career, when I was doing more electronics work. If I was looking for a “project”… this might be it. But if I was to do anything more with this at this late date, I’d more likely just 3d-print a frame to hold the little two-board set in a more compact form factor. Based on the relatively little interest this thread has generated, however, I doubt that it would ever be of interest to any but the most avid/tenacious and adventurous of users. Parallel-ports seem generally considered obsolete nowadays – sadly, they’re even disappearing from PCs – and, even if/when you can find one, it appears most folks really don’t want to mess with the bulk of the machine. Then if you are tenacious enough to set it up, you really have to be committed to making the time/effort learning to use it worthwhile. That’'s kind of where I found myself after I built this one up. And I’m just too old and tired to pursue it further… for just my own edification and benefit.

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So this is my question. Is the major energy for the LinuxCNC project because of sunk cost in original solution and folks just keep finding ways to extend the platform with hardware work arounds?

The control and variety of features is absolutely killer with it from what I can understand. The microcontroller path is still shaking out between the different firmware projects and thus some things work and some things don’t.

Is it fair to say that LinuxCNC is the open source solution that has the largest capabilities for driving whatever machine you want to drive with it? I am a huge Marco Reps fan. He is using LinuxCNC to drive his new mill. Seems very popular with the Germans.

These are basic questions, but I need to find a way to justify reading more and trying to understand it. Or should I just let it go because it will be harder and harder to have the computing interface to run it?

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The computing hardware and interface circuitry really aren’t a big deal, as I hope this thread demonstrates… practically zero cost for a discarded PC and maybe $20 (?) if you have to buy the little interface cards.

Forgive me if my memory isn’t entirely accurate… but Marlin/Grbl/other will never be classified as “serious” CNC controllers by the CNC snobs and purists out there. A 3d-printer is a small CNC machine at its core, of course, and it’s that built-in CNC capability that our hobbyist-quality DIY machines, such as MPCNC, are using… but these will always lack the features and power of commercial offerings; i.e. they offer only a “subset” of the power and features found in “serious” machines.

EMC2/LinuxCNC, on the other hand, was initially government sponsored public domain software for the control of milling machines, controlled by digital computers, back in the 1950s. It was to be “vendor-neutral” and a reference implementation of what was to become the industry standard language, gcode. Therefore, from the start, it was full-featured and a serious CNC control software for serious machines. IIRC Mach3 and many other commercial CNC softwares out there almost certainly “lifted”/benefitted from that early development.

Most hobbyists, of course, will never need that many features or that much power… even if it’s free. But knowing a bit of its history – that far pre-dates PCs and consumer computing equipment – shows that usage of the parallel-port wasn’t just a poor choice on somebody’s part… at the time, it was the “future” and made possible the inexpensive DIY CNC capabilities and equipment we know today.

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Thanks. That legacy stuff is what I was wondering about. It seems that there is a robust ecosystem of hardware to connect to whatever you come up with. It seems that Mesa is very common.

I have the computers to do this. Will keep poking around to get all the connecting bits figured out.

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Well now… I may have to review my little stockpile of “dead” computers. If anything looks viable, I’ll throw LinuxCNC on it, and see what I can do with it. I may have to invest in a driver shield/breakout, but I can harvest the A4988’s from my RAMPs knock-off…

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Interestingly, the pi basically has a parallel port on it. It has a ton of available io. Linux cnc uses a real time kernel, I think. So it’s non trivial to port it to the pi.

Sorry, it was easyeda.com. An online editor, goes straight to the manuf. <$20 later, and a few weeks and you’ll get a stack of boards. I found it very fun to make one (I’ve made a couple). If you got into it, you could build some fun stuff. I think you’d enjoy it, but feel free to disagree.

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Yeah, the Pi has plenty of IO…you just need the step and dir signals for each axis. It’s the real-time kernal that would be the problem, I’m sure… but apparently there are folks out there working on it

https://forum.linuxcnc.org/18-computer/36879-raspberry-pi-4

No doubt I could enjoy piddling with this kind of stuff… but I’ve already got more to do than the energy to do it. And there’s little I think we disagree on, Jeff… we seem pretty like-minded. But, even if we did disagree, you’d only need to throw the one punch and I’d be down for the count :rofl:

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:facepunch:

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A lot of those electronic youtubers are pushing JLPCB. Oh my gosh. I wish I were retired so I can jump in head over heels in this whole area. I have some drivers floating around.

I guess I’ll start reading the LinuxCNC forum and tutorials and brush up on what’s possible.

https://gnipsel.com/linuxcnc/uspace/

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Just please, stick around here too!

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Yes, please keep spending time here as well… the forum needs you. And I’ve enjoyed all the dialog here as well :smiley:

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You are stuck with me for sure here. Discourse has all those badges. There is one for Aficionado for 100 straight days and Devotee for 365 days. They are on my list.

I want to take the time to get pictures and document clearly my touch probe/puck and how I use it. There is stuff here, and the documents have it, but getting all the various board locations for everything clearly labeled and understood is a work in progress.

I’m going to keep poking around in LinuxCNC. The number of solutions for different machines is really amazing, especially in the robotic arm category.

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